AnsweredAssumed Answered

AD7730 Internal-zero-scale calibration

Question asked by KUAVmsc on Nov 30, 2015
Latest reply on Dec 14, 2015 by KUAVmsc

Hi, I am using the AD7730 and i have some problems with the Internal zero-scale calibration. I use the SPI interface to communicate between my uC and the AD converter.

I am able to wirte and read from the registers of the AD7730.

The converter is configured in bipolare mode, HIREF = 1( 5V ), Range : +-10mV, 16bit mode.

I am using two AD7730 parallel which are selected with two CHIP-Select.

 

After a calibration cycle the value of the corresponding Offset-Register changed by a very small value but there is still an offset(approx. 30150) to the expected value of 32768 when the input pins are shorted.

 

Has anyone any advices?

 

 

Outcomes